title: Inhibition of Neisseria gonorrhoeae isolates by Martin-Lewis medium. Epidemiology, susceptibility profile, and plasma analysis.
abstract: A study was undertaken on the premise that if an increase of 1 microgram/ml in the concentration of vancomycin in Martin-Lewis medium (MLM) could improve inhibition of Gram-positive cocci, then a concomitant increase in the inhibition of gonococci could also occur. Isolates of Neisseria gonorrhoeae that failed to grow on MLM accounted for 18-5% of all positive culture results for gonorrhoea. The incidence of isolates susceptible to vancomycin was 14% and of those susceptible to trimethoprim 2.4%; one isolate was susceptible to both vancomycin and trimethoprim. The antibiotic-susceptible isolates were more frequently isolated from asymptomatic white men. Plasmid analysis showed that the 2.4-megadalton cryptic plasmic was absent in the vancomycin-susceptible isolates. The large proportion of isolates failing to grow on selective MLM has important clinical implications for the diagnosis of gonorrhea.
mesh_terms: D003470:Culture Media / Q000494:pharmacology; D004587:Electrophoresis, Agar Gel; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D010957:Plasmids; D014295:Trimethoprim / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D014640:Vancomycin; D014295:Trimethoprim